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expert reaction to study looking at COVID-19 vaccination in early pregnancy and risk of congenital foetal anomalies

A study published in JAMA Pediatrics looks at COVID-19 vaccination during early pregnancy and risk of congenital fetal anomalies.


Dr Victoria Male, Lecturer in Reproductive Immunology, Imperial College London, said:

“This study adds to the extensive safety data we already have, with formal studies having already reported outcomes for more than 185,000 people who have received the COVID vaccine while pregnant and their babies.  None of these studies have found any increased risk of pregnancy problems following COVID-19 vaccination.  Nonetheless, this study adds important new information, because it tells us that there is no increased risk of congenital abnormalities specifically when the COVID-19 vaccine is given in early pregnancy when the fetus is developing.

“The study looked at everyone who was attending to have their anatomy scan at a Chicago hospital between March and November 2021.  Patients were divided into those who were vaccinated at the time the fetus is developing, between -2 and 14 weeks (1,473), those who were vaccinated after this critical window (1,149) and those who were unvaccinated (534).  The rate at which fetal anomalies were detected on scans were the same across all three groups – they were also the same when the authors looked only at those people vaccinated at the most vulnerable time, between weeks 2 and 10 of pregnancy.

“By comparing outcomes in people who received the vaccine at different times in pregnancy, the authors control for potential differences between the types of people who choose to get vaccinated and those who do not.  They also do a mathematical analysis to take into account factors such as age, how many babies the patient had already had, hypertension and haemoglobin level – although they did not have the information to control for whether the patients were taking folic acid, which is known to be a major determinant of the anomaly rate.  The study is also limited by the fact that it is relatively small.  However, taken in the context of everything else we know about the safety of COVID-19 vaccination in pregnancy, this adds to the wealth of reassuring data we already have.”



‘Association of COVID-19 vaccination during early pregnancy with risk of congenital fetal anomalies’ by Rachel S. Ruderman et al. was published in JAMA Pediatrics at 16:00 UK time on Monday 4 April 2022.

DOI: 10.1001/jamapediatrics.2022.0164



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